Braking device



Feb. 1, 1955 w. w. GOTTSCHALK BRAKING DEVICE Original ,Filed June 29,1948 INVENTOR WINSTON w- GOTTSCHALK ATTORNEY United States PatentBRAKING DEVICE Winston W. Gottschalk, Lancaster, Pa., assignor toArmstrong Cork Company, Lancaster, Pa., a corporation of PennsylvaniaOriginal application June 29, 1948, Serial No. 35,932. Divided and thisapplication July 2, 1951, Serial No. 234,850

3 Claims. (Cl. 188-84) This invention relates to a braking device, andmore particularly to a self-actuating braking device for quickly haltingrapidly rotating spindles on manufacturing equipment.

In the past, it has been common practice to employ braking devices whichare operated through a suitable linkage from an electric switch or amechanical tripping device of some sort. These devices are satisfactoryin most instances, but in many instances it is necessary to halt rapidlyrotating objects quickly and the linkage type braking mechanism is notsatisfactory due to the delay caused by the time cycle required for thelinkage mechanism to operate.

An example of the type of device which requires quick braking action isthe device illustrated and described in my copending application SerialNo. 35,932, filed June 29, 1948, entitled Trimming Device, of which thisapplication is a division.

In the device above referred to, a series of rapidly rotating spindlesis sequentially revolved about a central axis through a plurality ofprocessing stations. Each spindle carries a workpiece, and it isnecessary that the spindles be rotated during a portion of their path oftravel and that they be halted for the ejection of the workpiece and forthe insertion of a new workpiece. In this specific instance, the drumcarrying the spindles may be rotated from 3 R. P. M. to 20 R. P. M.Since the drum carries six spindles when operating at its maximum speedof 20 R. P. M., it is necessary to stop 120 spindles per minute, or twoper second. It will be obvious from this that braking mechanismsrequiring hydraulic or mechanical linkage would not be suitable toaccomplish the quick braking action required.

In order to provide a braking mechanism suitable for accomplishing thispurpose, the self-actuated brake disclosed herein has been developed.

In order that my invention may be more readily un derstood, it will bedescribed in connection with the accompanying drawing in which gigure 1is a top plan view of the braking mechanism; an

Figure 2 is a front elevational view of the braking mechanism.

Referring to the drawing, there is illustrated a self actuating brakemechanism 2 suitable for halting the rotation of the rotating spindle 3,which is provided on its lower extremity with a pulley 4. The purpose ofthe pulley 4 is to engage a belt during a certain portion of travel ofthe spindle in its circular path. The pulley 4 engages the belt, whichimparts rotation thereto, and the spindle is subsequently halted by theself-actuating brake mechanism engaging the pulley 4. In the operationof the braking mechanism, the spindle 3 with the pulley 4 moves into thebrake in a counterclockwise direction, as shown by the arrow inFigure 1. The pulley 4 is engaged by two arcuate brake shoes 5 and 6,which are of a shape to conform to the circumference of the pulley 4.When moving into the brake shoes 5 and 6, the pulley 4 first engages thebrake shoes at points 7 and 8 on the brake shoes 5 and 6, respectively.

Inasmuch as rotary motion of the carrier on which the spindle is mountedforces the pulley into the brake shoes, the brake shoes are permitted toseparate by means of the construction of the brake. The shoes 5 and 6are secured to rocker arms 9 and 10, respectively. The rocker arms 9 and10 are pivotally attached to the frame of the machine by means of bolts11 and 12. As the "ice rocker arms 9 and 10 are pivoted around the bolts11 and 12, springs 13 and 14 are compressed. As the pulley moves intothe center of the brake, springs 13 and 14 move rocker arms 9 and 10toward one another, carrying the brake shoes 5 and 6 with them. Thisspring action forces the brake shoes into engagement with the rotatingpulley 4, and the frictional drag stops the pulley. As the pulley 4moves out of the brake, it engages points 15 and 16 on the brake shoes 5and 6. The brake shoes 5 and 6 are secured to the rocker arms 9 and 10by means of pivot screws 17 and 18. As the brake shoes are forced apartat points 15 and 16, they pivot around points 17 and 18, and in sodoing, compress springs 19 and 20, thereby allowing the pulley to moveout of the brake. After the pulley is clear of the brake, springs 19 and20 urge the brake shoes back to their original position and the brake isready for the next succeeding pulley.

In order to prevent springs 13 and 14 from returning the rocker arms 9and 10 too far, I have limited this action by counterboring the rockerarms 9 and 10 in such manner thtat the enlarged ends 21 and 22 of thebolts passing through and holding the springs 13 and 14 contact theshoulder of the counterbored portion. The brake shoes 5 and 6 arecounterbored in a similar manner so that the enlarged heads 23 and 24 ofthe bolts holding the springs 19 and 20 will engage the shoulder of thecounterbored section. These bolt heads 21, 22, 23, and 24 prevent themovable parts of the brake assembly from moving too far over the actionof the springs.

In a brake of this type in which both ends of the brake shoe are springurged and the pressure exerted on the brake shoe is substantially thesame at both ends, a uniform pressure is exerted on the brake lining atall points along the arcuate surface of the brake. This causes uniformwear on the brake lining and exerts a pressure over a greater area ofthe rotating pulley, thereby gaining greater efficiency from the brake.

In many industrial machines it is necessary to stop a rotating spindlewhile it is positioned in one station for only a fraction of a second.It is, therefore, essential that the braking action be practicallyinstantaneous, and many of the conventional hydraulic and mechanicallinkage type brakes are impractical for accomplishing this purpose. Inthe device illustrated and described herein, the braking action iseffective from the instant the pulley touches the brake shoes until itleaves the brakes shoes.

In machines of the type here under consideration it is often necessaryor desirable to perform another operation at the same station at whichthe braking action is accomplished. In the particular device here underconsideration, the workpiece is ejected at the same station at which thebraking action is applied to the rotating spindle. This ejectionoperation is performed by the ejector mechanism shown generally at 25,which operates through the center of the brake support 26. This ejectoris raised by means of the cam-operated lever 27 and is lowered to itsinoperative position by means of the spring 28. This can be easilyaccomplished with a simple compact, self-contained, and self-actuatedbraking mechanism of the type herein disclosed which does not requireany external connections to control the same.

Another advantage in braking devices of this type is the small amount ofenergy which is lost through movement of the braking elements occasionedby the short distances the braking elements must move to accomplish thebraking action required.

Furthermore, the braking mechanism is easily disassembled andreassembled for repair and replacement of parts without the dismantlingof any portion of the machine to which it is affixed.

I claim:

1. A braking device comprising a pair of brake shoes positioned toengage a rotating pulley traveling in a circular path, each of saidbrake shoes being pivotally attached to a rocker arm which is in turnpivotally attached to a rigid support, the arrangement of said brakeshoes and said rocker arms being such that the brake shoes are forcedaway from one another by a pulley entering the device to be positionedbetween the brake shoes, a spring connecting each rocker arm to therigid support at the end of the rocker arm opposite the pivotalattachment to the support, said spring being compressed when the rockerarms are forced apart and serving to return the rocker arms to theiroriginal position when the pulley is properly positioned between theshoes, the end of each brake shoe opposite its pivotal attachment to therocker arm being connected to the rocker arm by means of a spring, saidspring being compressed when the shoes are forced apart as the pulley isleaving the brake assembly and serving to return the brake shoes totheir original position, and means to prevent the springs acting on therocker arms and the springs acting on the brake shoes from closing thebrake an excessive amount.

2. A braking device comprising a pair of spaced brake shoes positionedto engage a rotating pulley traveling in a predetermined path betweensaid brake shoes, each of said brake shoes being pivotally attached atone end to a rocker arm which is in turn pivotally attached at one endto a rigid support, the arrangement of said brake shoes and said rockerarms being such that the brake shoes are forced away from one another bysaid pulley moving into position between the brake shoes, resilientmeans connecting said rocker arm to the rigid support at the end of therocker arm opposite the pivotal attachment to said support, saidresilient means serving to return the rocker arm to its originalposition when the pulley is properly positioned between the brake shoes,the end of each brake shoe opposite its pivotal attachment to the rockerarm being connected to the rocker arm by resilient means capable offorcing the brake shoe into contact with the periphery of a rotatingpulley, and means for preventing the resilient means from returning thebrake shoes an excessive amount.

3. A braking device comprising a pair of spaced brake shoes tosequentially engage a plurality of rotating pulleys traveling in apredetermined path between said brake shoes, each of said brake shoesbeing pivotally attached at one end to a rocker arm which is in turnpivotally attached at one end to a rigid support, the engagement of saidbrake shoes with said rocker arms being such that the brake shoes areforced away from one another by said pulleys entering the device andleaving the device, resilient means connecting each rocker arm to therigid support at the end of the rocker arm opposite the pivotalattachment to said support, and resilient means connecting said brakeshoes to said rocker arms at the end opposite the pivotal attachment ofthe brake shoes to the rocker arms, both of said resilient means servingto urge said brake shoes into uniform engagement with the periphery of apulley positioned between the shoes and to return the brake to closedposition after one pulley has left and before the next one is receivedtherein.

References Cited in the file of this patent UNITED STATES PATENTS1,315,874 Smythe Sept. 9, 1919 1,824,150 Howe Sept. 22, 1931 2,233,798Robins Mar. 4, 1941

